arch: Use CONFIG_XPL_BUILD instead of CONFIG_SPL_BUILD

Use the new symbol to refer to any 'SPL' build, including TPL and VPL

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/Makefile b/arch/arm/cpu/armv8/fsl-layerscape/Makefile
index eefdf12..e2033dc 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/Makefile
+++ b/arch/arm/cpu/armv8/fsl-layerscape/Makefile
@@ -5,7 +5,7 @@
 obj-y += cpu.o
 obj-y += lowlevel.o
 obj-y += soc.o
-ifndef CONFIG_SPL_BUILD
+ifndef CONFIG_XPL_BUILD
 obj-$(CONFIG_MP) += mp.o spintable.o
 obj-$(CONFIG_OF_LIBFDT) += fdt.o
 endif